I have a minimized safe Rust witness for xxhash-rust 0.8.15.
Safe public route:
xxhash_rust::xxh3::xxh3_64_with_secret(&[0x41], &[])
The caller-side harness contains no unsafe code. Under release execution, the internal minimum custom-secret length predicate is enforced only by debug_assert!. Release-Miri reports construction of a fixed-width reference beyond the empty secret allocation.
Observed diagnostic:
Undefined Behavior: constructing invalid value of type &[u8; 4]: encountered a dangling reference
Local repair evidence: handling custom-secret slices shorter than the internal minimum before fixed-width secret reads makes the same safe short-secret harness pass under Linux release-Miri.
Local artifacts:
{
"cwe_ids": [
"CWE-125"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-02T18:29:13Z",
"nvd_published_at": null,
"severity": "LOW"
}